Related Experiment Video
Updated: Aug 14, 2026
Taste Exam: A Brief and Validated Test
Published on: August 17, 2018
Objective assessment of terbinafine-induced taste loss
Richard L Doty1, Boris R Haxel
1Department of Otorhinolaryngology-Head and Neck Surgery, Smell and Taste Center, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA. doty@mail.med.upenn.edu
Objectives:
Terbinafine (Lamisil), a widely prescribed oral antifungal agent, reportedly induces taste loss in 0.6% to 2.8% of those taking the drug. However, many so-called taste problems reflect olfactory problems, and the sole empirical study published on this topic, based on whole-mouth testing of a single subject, found no terbinafine-related deficit. In this study, we quantitatively assessed, using well-validated taste and smell tests, chemosensory function in six patients complaining of taste disturbance after terbinafine treatment and compared their test scores to those of six age-, race-, and sex-matched normal controls.
Methods:
Taste function was measured using a 96-trial regional test that assesses sweet, sour, bitter, and salty taste perception within the anterior (cranial nerve [CN] VII) and posterior (CN IX) lingual taste bud fields. Smell function was bilaterally evaluated using the 40-item University of Pennsylvania Smell Identification Test.
Results:
Taste function for sweet-, sour-, and bitter-tasting stimuli was significantly depressed in both the anterior and posterior lingual regions. For sodium chloride, the decrements were confined to the posterior region. Olfactory function was within normal limits.
Conclusion:
These findings 1) support anecdotal case reports of taste loss after terbinafine use, 2) demonstrate that all four major taste qualities are affected, and 3) suggest that olfactory dysfunction is not involved. Because self-report markedly underestimates chemosensory deficits, more extensive quantitative testing of patients receiving terbinafine will likely reveal a much higher prevalence of terbinafine-induced taste loss than currently reported. Since being older than 65 years of age and having a low body mass index are reportedly risk factors for terbinafine-induced taste loss, physicians should be particularly on the alert for elderly persons taking this medication who may become depressed or alter their food intake in response to decreased taste sensation.
Insights
Oral terbinafine can cause taste loss, affecting all four basic taste qualities. This study found significant taste deficits in patients, suggesting current estimates of taste loss prevalence may be underestimated.
Area of Science:
- Neuroscience
- Pharmacology
- Sensory Science
Background:
- Terbinafine (Lamisil) is a common oral antifungal medication.
- Reported taste loss occurs in 0.6%–2.8% of patients, but this may be underestimated.
- Previous studies on terbinafine's effect on taste are limited.
Purpose of the Study:
- To quantitatively assess taste and smell function in patients reporting taste disturbance after terbinafine treatment.
- To compare chemosensory function in terbinafine users with healthy controls.
Main Methods:
- Quantitative assessment of taste function using a 96-trial regional test for sweet, sour, bitter, and salty stimuli.
- Evaluation of smell function using the University of Pennsylvania Smell Identification Test.
- Comparison of six terbinafine patients with six matched controls.
Main Results:
- Significant depression in taste function for sweet, sour, and bitter stimuli in both anterior and posterior tongue regions.
- Decreased salty taste perception (sodium chloride) was localized to the posterior tongue.
- Olfactory function remained within normal limits in all patients.
Conclusions:
- Findings support anecdotal reports of terbinafine-induced taste loss.
- All four major taste qualities are affected, and olfactory dysfunction is not implicated.
- Quantitative testing reveals a higher prevalence of taste loss than self-reports suggest; elderly patients are at higher risk.
